Prostate gland secretions from

Fructose is synthesised in the prostate gland. It is secreted into the seminal fluid as the fuel for sperm. It is synthesised from glucose as follows... 

Figure 19.1 A diagrammatic representation of the male reproductive tract. Much of the volume of the testes consists of convoluted seminiferous tubules in which the spermatozoa form. In the interstitial tissue that surrounds the seminiferous tubules are the Leydig cells which produce and secrete androgens, oes-tradiol and the peptides inhibin and activin. The epididymis is a single but convoluted tube. Sperm from the epididymis enter the vas deferens and pass through the ejaculatory duct into the urethra, mainly at the time of ejaculation. Just at the transition of the vas deferens to ejaculatory duct, two large glands, the seminal vesicles, drain into the two vasa deferentia. Prior to joining the urethra, the ejaculatory ducts pass through the prostate gland which lies below the bladder and surrounds the upper part of the urethra, into which prostatic fluid is secreted.

The prostate gland and the seminal vesicles secrete the bulk of the fluid. The sources, contents and functions of the secretions from the accessory glands are given in Table 19.1. 

The prostaglandins are a group of modified C20 fatty acids first isolated from human semen and initially assumed to be secreted by the prostate gland. They are now known to occur widely in animal tissues, but only in tiny amounts, and they have been found to exert a wide variety of pharmacological effects on humans and animals. They are active at very low, hormone-like concentrations and can regulate blood pressure, contractions of smooth... 

Prostaglandins are fatty acid derivatives that are even more powerful biochemical regulators than steroids. They are called prostaglandins because they were first isolated from secretions of the prostate gland. They were later found to be present in all body tissues and fluids, usually in minute quantities. Prostaglandins affect many body systems, including the nervous system, smooth muscle, blood, and the reproductive system. They play important roles in regulating such diverse functions as blood... 

This gronp of compounds was given its name because the first prostaglandins were identified from the secretions of the male prostate gland. Recent research has identified as many as 20 prostaglandins in a variety of tissnes within both males and fanales. 

Seminal vesicle secretions from many species are known to harbor a large number of enzymes, many of which may simply originate from the cytoplasm of the secretory epithelial cells and play no functional roles in seminal plasma. Comprehensive accounts of the enzyme muster of vesicular secretions are provided in several treatises (1, 4, 5, 215). Only vesicular secretion enzymes that are of potential regulatory significance will be considered here. It is noteworthy that many highly active enzymes in seminal plasma originate from the epididymis and(or) the prostate gland (4, 5). 

An intriguing unsolved problem from a regulatory standpoint is the mechanism of citrate accumulation and secretion by seminal vesicle and/or other male accessory glands. How citrate accumulates substan-tieilly in bone (296) and is secreted into milk by lactating mammary gland (297) is also not understood. Early studies on dog (298) and rat ventral prostate (299) disclosed that citrate is readily formed from oxaloacetate and pyruvate (or acetyl-CoA) and demonstrated many other reactions of the mitochondrial tricarboxylic acid cycle. Seminal... 

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